An endoscopy capsule, which can fulfill various medical objectives, is introduced into a patient in magnetically guided capsule endoscopy (MGCE). The capsule contains a magnetic element, by which a force or torque can be exerted onto the capsule by applying an external magnetic field. The capsule can be advanced without contact within the patient by targeted application of force and there it can accordingly achieve medical objectives.
The external magnetic field for exerting a force onto the capsule is produced by a so-called guidance magnet, which is arranged outside of the patient. A corresponding solenoid system has been disclosed in e.g. DE 103 40 925 B3.
The inventors considered a specific application of MGCE, namely esophagogastroduodenoscopy (EGD), in which it is precisely only esophagus and stomach and optionally also the duodenum of a patient that can be reached with the aid of capsule endoscopy.
For the purpose of such an EGD examination, the stomach is filled, e.g. half full or more, with water. The capsule has a volume of approximately 2-3 cm3. The endoscopy capsule with a mass of approximately 2-3 g is embodied with an appropriate density which is close to, preferably just below, that of water. The endoscopy capsule then floats in the water in the stomach and, together with its buoyancy, has an effective mass of e.g. −0.1 g. The installed equipment in the capsule is arranged such that the center of gravity of the capsule on the longitudinal axis of the capsule is situated at a slight distance from the center of the capsule. The elongated capsule is therefore perpendicular in the water if no external forces are applied; the camera thereof installed at the tip faces downward in the rest state.
By using an appropriate guidance magnet, it is possible to pull the capsule below the water surface in the stomach against its buoyancy, displace it horizontally and tilt it. In this corresponding specific application of MGCE, only substantially reduced forces need to be exerted onto the capsule in comparison to the case in which the latter is to be moved through the whole intestinal tract of the patient.
Compared to the aforementioned general solenoid system, the present EGD application therefore merely makes use of a so-called EGD guidance magnet which can have a substantially simpler design than the one described in DE 103 40 925 B3. By way of example, DE 10 2008 004 871 A1 has disclosed a coil arrangement for contactless guidance of an endoscopy capsule. Furthermore, by way of example, use is made in a corresponding magnet system of a coil cooling concept from DE 10 2007 007 801 A1.
Moreover, WO 2006/014011 A1 has disclosed an alternative EGD guidance magnet: the magnet system consists of three coils, which, together, form a so-called block magnet. This block magnetic is arranged under a patient table and can, below the latter, be mechanically displaced in two dimensions. The patient table can alternatively be displaced relative to the block magnet in two dimensions. The access to a patient, who is arranged on the upper side of the patient table, is not impeded by the block magnet.